CSIRO hails 'game-changing' solar breakthrough

Australia’s research organisation CSIRO has generated ‘supercritical’ steam using solar power at temperatures only previously achieved with fossil fuels.

The breakthrough means that one day the Sun could be used to drive the most advanced power stations in the world, currently only driven by coal or gas.

CSIRO’s energy director, Dr Alex Wonhas, said this milestone is a game-changer for the renewable energy industry. “It’s like breaking the sound barrier; this step change proves solar has the potential to compete with the peak performance capabilities of fossil fuel sources,” he said.

About 90 per cent of Australia’s electricity is generated using fossil fuel, but only a small number of power stations are based on the more advanced supercritical steam.

CSIRO set a world record in May this year by producing supercritical solar steam at a pressure of 23.5MPa and temperatures up to 570°C. It is the combination of pressure and temperature demonstrated at scale that makes this such a breakthrough for solar power.

Commercial solar thermal power plants around the world use subcritical steam, operating at similar temperatures but at lower pressure. If these plants were able to move to supercritical steam, it would increase the efficiency and help to lower the cost of solar electricity.

The AU$9.7m (£5.3m) research programme is supported by the Australian Renewable Energy Agency (ARENA) and is part of a broader collaboration with Abengoa Solar, the largest supplier of solar thermal electricity in the world. CSIRO and Abengoa Solar, with support from ARENA, are developing advanced energy storage to provide solar electricity at any time, day or night.

The breakthrough was made at the CSIRO Energy Centre in Newcastle, New South Wales. The centre has two solar thermal test plants featuring more than 600 mirrors (heliostats) directed at towers housing solar receivers and turbines.

Although there is still work to be done before this technology is ready for commercialisation, ARENA CEO Ivor Frischknecht acknowledged the significant achievement, saying it demonstrated the importance of research and development.